Management of adverse events related to new cancer immunotherapy (immune checkpoint inhibitors)

The well researched narrative review by Bourke and colleagues1 offers a comprehensive overview of immune-related adverse events (irAEs) in cancer immunotherapy and their management. However, care needs to be taken in adopting too broad an approach, particularly in relation to dermatological irAEs.

In the article, “rash” is described as an irAE. However, a rash is a clinical sign, not a diagnosis. The cutaneous irAEs reported in association with immune checkpoint inhibitor therapy span a spectrum of dermatoses including (but not limited to) vitiligo, eczema, lichenoid reactions, morbilliform eruptions, prurigo nodularis, bullous pemphigoid, papulopustular eruptions, rosacea, and cutaneous fungal, bacterial and viral infections.2,3 Categorising every cutaneous irAE as a rash precludes patients from obtaining an accurate diagnosis, which in turn encumbers treatment. Topical corticosteroids are a reasonable first-line treatment option for most pathologies (unless the cutaneous irAE is an infection or papulopustular eruption). However, there is a range of corticosteroid molecules, potencies and vehicles, as well as off-formulary preparations available,4 and physicians should be familiar with this class of drugs before prescribing them. Where accurate diagnosis of a cutaneous irAE becomes particularly important is when topical corticosteroids fail. Systemic corticosteroids, while helpful in containing an acute disease process, are seldom the second-line treatment employed by dermatologists. Dermatologists have an arsenal of topical, physical and systemic therapies at their disposal, and the choice of second-line treatment is determined according to diagnosis. We would therefore offer that a multidisciplinary approach is important in the management of the cutaneous toxicities of the new generation of oncological treatments; not only the moderate and severe as suggested, but also the mild and life-threatening.

We commend the rapid rate at which our colleagues in medical oncology have become versed in the fundamentals of dermatological care and recognise only too well the limitations in access to dermatology, even in many of the larger teaching hospitals across Australia.5 However, in many respects, this new era of immunotherapy is uncharted territory, and managing the cutaneous toxicities of these medications necessitates an appreciation of the nuances of managing skin disease.